Present day wireless communication utilizes radio waves as a carrier to transmit voice and/or data. Digitized voice and multimedia data is used to modulate radio frequency (RF) channels that carry the signals from a mobile device, for example, to a base station. Typically, both the base station and the mobile terminal use a limited amount of power to transmit the signal, which results in covering only a limited geographical area. Thus, outside the geographical area of coverage, frequency channels may be reused. The basic management unit for access to cellular services is the area covered by a base station—the cell—can be divided into sectors to reduce interference between adjacent cells. Because of the limited number of service channels that can be accessed in a given area covered by a base station, the number of simultaneous communications that can be carried out in a given coverage area is also limited.
When the number of service requirements for voice or data exchange within a coverage area exceeds the number of channels available, any new service request must be rejected, which is known as a blocked call. Under these conditions it is said that the network is in a state of congestion. The percentage of calls that are blocked is defined as the grade of service. Thus, a 2% grade of service means that two (2) out of one hundred (100) calls will be blocked and their service request cannot be handled at any given time, on the average. Service providers try to keep the number of rejected service requests reasonable and within regulation guidelines. To establish the grade of service, network administrators rely on performance curves and equivalent tables generated by mathematical models, among which the best-known being the Erlang B and Erlang C models. The latter models define the probability that a request for voice communication service will be granted, rejected, or delayed.
In the case of a moving mobile device, such as a mobile phone, calls in progress on mobile phones on the edge of a cell sector's service area must be transferred to a neighboring base station, in order to maintain service. The latter is achieved by seamlessly transitioning from a weak signal from a base station to a stronger signal from a next (closer) base station. This process is called handover (HO). The handover is possible only if the neighboring cell sector has a channel available for this purpose. Otherwise, the call will be dropped.
Service providers tend to avoid dropping calls because it is more annoying for subscribers than being unable to initiate a new call. The latter condition creates two service access priority levels: handover level and new call level, with handover requests having a higher priority than new call requests. To ensure there are enough channels available to support handover requests at times of congestion, a predetermined number of channels in a cell sector are reserved for that purpose. This means that the probability of accepting a handover request is much greater than the probability of allowing a new call request. Therefore, a new call initiated within the cell sector will be rejected if the only channels available are the ones reserved for handovers.
Existing methods, such as Erlang B and C mathematical models, do not consider priority access. Mobile network administrators of existing systems rely on their own professional experience in order to reserve channels for handovers.
Some prior art technologies attempt to address the issue of managing wireless connections in order to optimize the efficiency of the wireless networks. In “Performance Analysis of a Channel Allocation Scheme with Preemptive Priority for Integrated Voice/Data Mobile Networks”, published in the 24th IEEE International Performance, Computing, and Communications Conference, 2005, (IPCCC 2005), S. Tang and W. Li, present an analytical model that dynamically adjusts three categories of channels to two service levels of voice and data traffic. Data calls may be dropped in case voice calls are transferred in from an adjacent cell sector, and no channels are available. The publication provides some curves to establish blocking probabilities for both services as a function of the total traffic load and the number of channels.
In “Capacity Optimizing Channel Allocation Scheme Supporting Multiple Services with Mobile Users in Cellular System” published in IEEE GLOBECOM 2005 Proceedings, M. Yang and P. H. J. Chong study the performance of a channel assignment (Channel Partitioning: CP) to support two levels of services (voice and data) with different reuse and signal interference factors for mobile users in a cellular system. They also provide blocking probabilities for each type of service.
U.S. Pat. No. 6,484,145 B1, entitled “Priority Access Channel Reservation” by S. L. Home C. Chern, published Nov. 19, 2002, presents a priority channel allocation method, limiting the amount of available channels to maintain a constant blocking probability. This method requires setting up a targeted blocking rate to the first priority level, using the Erlang B model to start the system. Then this blocking rate is dynamically adjusted. The problem with this procedure is that it requires constant monitoring of dynamic traffic statistics to ensure that constant blocking probability is maintained for the higher priority service class. This implies a use of computational resources that compromises overall network performance. Another problem is that the Erlang B model does not represent the initial situation well, resulting in settings that need adjustment.
The U.S. Pat. No. 7,006,831 “Apparatus and Method for Providing Dynamic Network Traffic Control Communications,” by W. R. Matz, D. R. O'Neil, J. R. Bacon and V. Meadows, published Feb. 28, 2006, presents a method of prioritized active or passive channel allocation to be implemented in geographical locations that experience high-traffic periods. Active monitoring is done by blocking, delaying, or cutting off calls in the system, whereas the passive control gives the user the option (preferably via SMS) to select a higher priority service to make the call for an additional fee. This invention describes the technical and business aspects involved in providing a priority channel assignment.
The U.S. Pat. No. 6,760,594 B1, “Method of Connecting Priority Call in Wireless Communication System and Apparatus for Achieving Method” by S. Murasawa and R. Ishibashi, published Jul. 6, 2004, presents a method for establishing priority calls using physical constraints and software thresholds in CDMA systems. Note that priority calls, as considered in this patent, are for emergency situation applications.
The publication U.S. 2006135117 A1, of Jun. 22, 2006, entitled “Method for providing paying services, user identification device, and device for providing said services” by J. Laumen, A. Schmidt, and S. Van Niekerk, describes a payment method for services of a GSM communications network. This method for exchanging messages between the user and service provider can be used to negotiate access privileges for users that do not have them. A radio communications terminal with a user identification device and a device for payment services is provided.
There is a need for a method and system that allows for establishing connection to a telecommunication network based on access privileges assigned to users.